CDRIVER-4346 unskip /BulkOperation/split (#1438)

* unskip `/BulkOperation/split`

* use session in test operations

* apply read and write concern majority

* skip test if no sessions support

Author: kevinAlbs

.evergreen/etc/skip-tests.txt

@@ -26,7 +26,6 @@
 /mongohouse/runCommand # CDRIVER-4333
 
 /change_stream/live/track_resume_token # (CDRIVER-4344) Condition 'bson_compare (resume_token, &doc2_rt) == 0' failed
-/BulkOperation/split # (CDRIVER-4346) Assert Failure: count of split_1512376901_50824 is 97759, not 100010
 /ClientPool/pop_timeout # (CDRIVER-4348) precondition failed: duration_usec / 1000 >= 1990
 /Client/get_handshake_hello_response/pooled # (CDRIVER-4349) Assert Failure: "Unknown" != "PossiblePrimary"
 

src/libmongoc/tests/test-mongoc-bulk.c

@@ -3485,19 +3485,21 @@ test_numerous_unordered (void *ctx)
 
 
 static void
-test_bulk_split (void)
+test_bulk_split (void *ctx)
 {
+   BSON_UNUSED (ctx);
+
    mongoc_client_t *client;
    mongoc_collection_t *collection;
    bson_t opts = BSON_INITIALIZER;
    mongoc_bulk_operation_t *bulk_op;
-   mongoc_write_concern_t *wc = mongoc_write_concern_new ();
    bson_iter_t iter, error_iter, indexnum;
    bson_t doc, result;
    bson_error_t error;
    int n_docs;
    int i;
    uint32_t r;
+   mongoc_client_session_t *session;
 
    /* ensure we need two batches */
    n_docs = (int) test_framework_max_write_batch_size () + 10;
@@ -3508,10 +3510,35 @@ test_bulk_split (void)
    collection = get_test_collection (client, "split");
    BSON_ASSERT (collection);
 
-   mongoc_write_concern_set_w (wc, 1);
+   // Apply settings to guarantee "read-your-own-writes" semantics.
+   // Intended to address undercounts reading results reported in CDRIVER-4346.
+   {
+      // https://www.mongodb.com/docs/manual/core/read-isolation-consistency-recency/#client-sessions-and-causal-consistency-guarantees
+      // describes how to guarantee "read-your-own-writes".
+
+      // Start a causally consistent session.
+      mongoc_session_opt_t *sopts = mongoc_session_opts_new ();
+      mongoc_session_opts_set_causal_consistency (sopts, true);
+      session = mongoc_client_start_session (client, sopts, NULL);
+      mongoc_session_opts_destroy (sopts);
+
+      // Apply read concern majority.
+      mongoc_read_concern_t *rc = mongoc_read_concern_new ();
+      mongoc_read_concern_set_level (rc, MONGOC_READ_CONCERN_LEVEL_MAJORITY);
+      mongoc_collection_set_read_concern (collection, rc);
+      mongoc_read_concern_destroy (rc);
+
+      // Apply write concern majority.
+      mongoc_write_concern_t *wc = mongoc_write_concern_new ();
+      mongoc_write_concern_set_w (wc, MONGOC_WRITE_CONCERN_W_MAJORITY);
+      mongoc_collection_set_write_concern (collection, wc);
+      mongoc_write_concern_destroy (wc);
+   }
+
 
-   mongoc_write_concern_append (wc, &opts);
    bson_append_bool (&opts, "ordered", 7, false);
+   ASSERT_OR_PRINT (mongoc_client_session_append (session, &opts, &error),
+                    error);
    bulk_op =
       mongoc_collection_create_bulk_operation_with_opts (collection, &opts);
 
@@ -3548,7 +3575,20 @@ test_bulk_split (void)
    BSON_ASSERT (!r);
 
    /* all 100,010 docs were inserted, either by the first or second bulk op */
-   ASSERT_COUNT (n_docs, collection);
+   {
+      bson_t count_opts = BSON_INITIALIZER;
+      ASSERT_OR_PRINT (
+         mongoc_client_session_append (session, &count_opts, &error), error);
+      int64_t count = mongoc_collection_count_documents (collection,
+                                                         tmp_bson ("{}"),
+                                                         &count_opts,
+                                                         NULL /* read_prefs */,
+                                                         NULL /* reply */,
+                                                         &error);
+      ASSERT_OR_PRINT (count != -1, error);
+      ASSERT_CMPINT64 (count, ==, 100010);
+      bson_destroy (&count_opts);
+   }
 
    /* result like {writeErrors: [{index: i, code: n, errmsg: ''}, ... ]} */
    bson_iter_init_find (&iter, &result, "writeErrors");
@@ -3574,9 +3614,8 @@ test_bulk_split (void)
    bson_destroy (&opts);
    bson_destroy (&result);
 
-   mongoc_write_concern_destroy (wc);
-
    mongoc_collection_destroy (collection);
+   mongoc_client_session_destroy (session);
    mongoc_client_destroy (client);
 }
 
@@ -5293,7 +5332,12 @@ test_bulk_install (TestSuite *suite)
       suite, "/BulkOperation/OP_MSG/max_batch_size", test_bulk_max_batch_size);
    TestSuite_AddLive (
       suite, "/BulkOperation/OP_MSG/max_msg_size", test_bulk_max_msg_size);
-   TestSuite_AddLive (suite, "/BulkOperation/split", test_bulk_split);
+   TestSuite_AddFull (suite,
+                      "/BulkOperation/split",
+                      test_bulk_split,
+                      NULL /* dtor */,
+                      NULL /* ctx */,
+                      test_framework_skip_if_no_sessions);
    TestSuite_AddFull (suite,
                       "/BulkOperation/write_concern/split",
                       test_bulk_write_concern_split,